As in most other social service systems, the status of men as fathers is not typically acknowledged in the conceptualization and delivery of substance abuse treatment. Although there has been extensive discussion of the need for parent intervention for drug-dependent mothers, there has been little consideration of the need for complementary intervention for drug-dependent fathers. Consequently, this Stage I psychotherapy development project will focus on the development, manualization, and initial evaluation of a relational parent intervention for methadone- maintained fathers with minor children and ongoing abuse of opioids, other drugs, or alcohol. This 26-week group psychotherapy will be grounded in a developmental-ecological perspective on parenting, and the intervention will be structured to move men through a process of behavior change designed to improve parent-child relationships and decrease substance use. Throughout the treatment, motivational and interpersonal techniques will be used to (1) highlight ways substance abuse interferes with parenting, (2) facilitate relationship building, and (3) explore ways commitment to parenting might be used to support abstinence. Over the course of 36 months, a systematic, goal-oriented approach to the development of psychosocial treatments will be used to realize four specific aims. First, guidelines outlined by Carroll and Nuro (1997) will be used to develop a comprehensive treatment manual that will define the intervention and guide delivery to the target population. Second, procedures outlined by Waltz et al (1993) will be used to develop psychotherapy process measures needed to document (1) adherence to the treatment protocol, (2) the clinical competence of group leaders, and (3) critical dimensions of the behavior change process. Third, content drawn from a preliminary group done with eight methadone-maintained men will be used to develop educational materials for use with clinicians, and procedures similar to those outlined by Rounsaville et al. (1984) will be developed to guide the selection, training, and supervision of group leaders. Finally, a randomized pilot study done with 64 methadone- maintained fathers will be used to evaluate the feasibility, discriminability, and potential efficacy of the proposed intervention when compared with a manualized version of group drug counseling that best represents treatment as usual.